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Observations of rapidly rotating solar-like stars show a significant mixture of opposite-polarity magnetic fields within their polar regions. To explain these observations, models describing the surface transport of magnetic flux demand the…

Astrophysics · Physics 2009-11-11 V. Holzwarth , D. H. Mackay , M. Jardine

Flux-dominated solar dynamo models have demonstrated to reproduce the main features of the large scale solar magnetic cycle, however the use of a solar like differential rotation profile implies in the the formation of strong toroidal…

Astrophysics · Physics 2009-11-13 G. A. Guerrero , E. M. de G. Dal Pino

Predictions of solar cycle 24 obtained from advection-dominated and diffusion-dominated kinematic dynamo models are different if the Babcock-Leighton mechanism is the only source of the poloidal field. Yeates et al. (2008) argue that the…

Solar and Stellar Astrophysics · Physics 2020-10-07 Soumitra Hazra , Allan Sacha Brun , Dibyendu Nandy

We investigate whether the Babcock-Leighton flux-transport dynamo model remains in agreement with observations if the meridional flow profile is taken from helioseismic inversions. Additionally, we investigate the effect of the loss of…

Solar and Stellar Astrophysics · Physics 2023-12-13 S. Cloutier , R. H. Cameron , L. Gizon

Observations show that faster-rotating stars tend to have stronger magnetic activity and shorter magnetic cycles. The cyclical magnetic activity of the Sun and stars is believed to be driven by the dynamo process. The success of the…

Solar and Stellar Astrophysics · Physics 2024-06-05 Zebin Zhang , Jie Jiang , Leonid Kitchatinov

We perform idealised numerical simulations of magnetic buoyancy instabilities in a model of the solar tachocline. We introduce a simplified model of magnetic flux pumping in an upper layer (the convection zone), and study the effects of its…

Solar and Stellar Astrophysics · Physics 2015-06-04 Adrian J. Barker , Lara J. Silvers , Michael R. E. Proctor , Nigel O. Weiss

At present, Babcock-Leighton flux transport solar dynamo models appear as the most promising model for explaining diverse observational aspects of the sunspot cycle. The success of these flux transport dynamo models is largely dependent…

Solar and Stellar Astrophysics · Physics 2016-11-15 Soumitra Hazra , Dibyendu Nandy

Context. In local helioseismology, the travel times of acoustic waves propagating in opposite directions along the same meridian inform us about horizontal flows in the north-south direction. The longitudinal averages of the north-south…

Solar and Stellar Astrophysics · Physics 2022-08-31 Paul-Louis Poulier , Zhi-Chao Liang , Damien Fournier , Laurent Gizon

Global and semi-global convective dynamo simulations of solar-like stars are known to show a transition from an anti-solar (fast poles, slow equator) to solar-like (fast equator, slow poles) differential rotation (DR) for increasing…

Solar and Stellar Astrophysics · Physics 2019-11-25 M. Viviani , M. J. Käpylä , J. Warnecke , P. J. Käpylä , M. Rheinhardt

The magnetic fields in the solar polar region are important to our understanding of the internal dynamo process, the global coronal structure, and the origin of the solar wind. The inference of polar fields based on spectropolarimetric…

Solar and Stellar Astrophysics · Physics 2026-03-16 Bryan Yamashiro , Xudong Sun , Ivan Milić , Carlos Quintero Noda , Adur Pastor Yabar , Rebecca Centeno , Jiayi Liu , Milan Gošić , Kai Yang

We present a realistic numerical model of sunspot and active region formation based on the emergence of flux bundles generated in a solar convective dynamo. To this end we use the magnetic and velocity fields in a horizontal layer near the…

Solar and Stellar Astrophysics · Physics 2017-09-20 Feng Chen , Matthias Rempel , Yuhong Fan

Various models of solar sub-surface stratification are tested in the global EULAG-MHD solver to simulate diverse regimes of near-surface convective transport. Sub- and superadiabacity are altered at the surface of the model ($ r >…

Solar and Stellar Astrophysics · Physics 2019-11-19 Andrey M. Stejko , Gustavo Guerrero , Alexander G. Kosovichev , Piotr K. Smolarkiewicz

We present the first global, three-dimensional simulations of solar/stellar convection that take into account the influence of magnetic flux emergence by means of the Babcock-Leighton (BL) mechanism. We have shown that the inclusion of a BL…

Solar and Stellar Astrophysics · Physics 2015-06-03 Mark S. Miesch , Benjamin P. Brown

Context. Local helioseismology has detected spatially extended converging surface flows into solar active regions. These play an important role in flux-transport models of the solar dynamo. Aims. We aim to validate the existence of the…

Solar and Stellar Astrophysics · Physics 2017-10-04 B. Löptien , A. C. Birch , T. L. Duvall , L. Gizon , B. Proxauf , J. Schou

Sunspots are obvious observable manifestations of the toroidal magnetic field generated through the dynamo in the convection zone. They appear in different sizes, having a wide distribution in their area. We analyse the sunspot group area…

Solar and Stellar Astrophysics · Physics 2026-02-10 Bidya Binay Karak , Soumya Mishra , Anu Sreedevi

Observations reveal a relatively small but statistically significant North-South (NS) asymmetry in sunspot activity varying on a time scale of several solar cycles. This paper proposes a dynamo model for the phenomenon of long-term NS…

Solar and Stellar Astrophysics · Physics 2021-09-29 Leonid Kitchatinov , Anna Khlystova

Decay and dispersal of the tilted Bipolar Magnetic Regions (BMRs) on the solar surface are observed to produce large-scale poloidal field, which acts as the seed for the toroidal field and, thus, the next sunspot cycle. However, various…

Solar and Stellar Astrophysics · Physics 2024-04-17 Pawan Kumar , Bidya Binay Karak , Anu Sreedevi

In this paper we complete the presentation of a new hybrid $2\times2$D flux transport dynamo (FTD) model of the solar cycle based on the Babcock-Leighton mechanism of poloidal magnetic field regeneration via the surface decay of bipolar…

Solar and Stellar Astrophysics · Physics 2017-09-26 Alexandre Lemerle , Paul Charbonneau

The Babcock-Leighton type of dynamo has received recent support in terms of the discovery in the observational records of systematic cycle-to-cycle variations in the tilt angle of sunspot groups. It has been proposed that these variations…

Solar and Stellar Astrophysics · Physics 2011-08-08 R. H. Cameron

Theoretical models for the solar dynamo range from simple low-dimensional ``toy models'' to complex 3D-MHD simulations. Here we mainly discuss appproaches that are motivated and guided by solar (and stellar) observations. We give a brief…

Solar and Stellar Astrophysics · Physics 2023-05-04 Robert Cameron , Manfred Schüssler